If you go to the Xylotex site, Jeff has a pdf file on the PACSci motors. - As I recall the dimensions are in there for all the PACSci NEMA 23 and up.
might try this link:
http://www.xylotex.com/Stepper%20Motors.htm I'll add page 51 of 108 in the pdf - there is a lot to wade thru
Cheers - Jim